Journal of Applied Science, Engineering and Technology

Effect of Acetylene Gas and LPG Gas Variations in the Oxy-Acetylene Welding Process on the Mechanical Properties of ST37 Steel Welded Joints

2026-07-01T00:44:23+00:00

Welding is a metal joining method widely used in manufacturing, construction, and metal component repair. Oxy-Acetylene Welding (OAW) is still a widely used welding method. This study aims to determine the effect of varying fuel gases in the Oxy-Acetylene Welding (OAW) process on the mechanical properties of joints made of low-carbon steel ST37. The gases used in this study were acetylene and LPG as fuel, with brass filler metal used. Mechanical properties were tested using tensile and impact tests. These tests aimed to determine the tensile strength and toughness of the welded joints produced by the two fuel gas variations. The results showed that the use of acetylene gas produced higher tensile strength values than LPG gas. The highest ultimate tensile strength value with acetylene gas reached 356.25 MPa, while the highest value with LPG gas was 275.05 MPa. Furthermore, the impact test results showed that welded joints using acetylene gas had higher absorbed energy than those welded with LPG gas. It was concluded that the type of fuel gas affects the quality of the weld joint. The use of acetylene gas provides higher tensile strength and impact toughness than LPG gas when welding low-carbon steel.

Evaluating Grounding Grid Safety in Renewable Energy Facilities Based on IEEE Std 80-2013 Using Spatial Voltage Distribution Modeling: A Case Study of Terbanggi Ilir Biogas Power Plant, Central Lampung

2026-07-05T09:18:28+00:00

Grounding grids in renewable energy facilities, such as biogas power plants, are critical for personnel safety and equipment protection during ground faults. This study evaluates the safety performance of the grounding grid at Terbanggi Ilir Biogas Power Plant in Central Lampung to validate its compliance with safety standards. Using the Finite Element Method (FEM) within Python Numerical Computation, 3D and 2D spatial voltage distribution profiles of the plant's asymmetric grounding grid—comprising 71 horizontal conductor (70 mm²) and 9 vertical rods (24 m) embedded in a two-layer soil model with a 0.2 m gravel surface layer—were simulated under a 25 kA fault current. The grid achieved a low resistance of 0.967 ohm, limiting the ground potential rise to 11.966 kV. The maximum calculated touch potential of 3.629 kV and step potential of 1.775 kV were both safely below the tolerable limits of 4.305kV and 16.555kV respectively, determined by IEEE Std 80 guidelines. The study concludes that the custom-tailored grid layout effectively mitigates electrical hazards, demonstrating that spatial voltage distribution modeling is vital for verifying earthing grid integrity in biogas power plant facilities.

Modification and Performance Testing of a Baglog Mixer Machine for Oyster Mushroom (Pleurotus ostreatus) Cultivation Medium

2026-07-05T18:03:08+00:00

Budidaya jamur tiram (Pleurotus ostreatus) bergantung pada media tanam homogen yang disebut baglog, yang terutama terdiri dari serbuk gergaji, sekam padi, dedak, kapur, dan air. Metode pencampuran manual tidak efisien, memakan waktu, dan menghasilkan campuran yang tidak seragam, sehingga mengurangi kualitas pertumbuhan miselium. Studi ini menyajikan modifikasi dan evaluasi kinerja mesin pencampur baglog yang awalnya dirancang oleh Teguh (2017) yang menunjukkan tumpahan material dari drum pencampur dan kapasitas keluaran material yang tidak memadai. Modifikasi tersebut melibatkan perancangan ulang perpanjangan tinggi drum pencampur menggunakan rangka batang sudut (40 mm × 40 mm), pemasangan lembaran seng galvanis, dan penambahan mekanisme pembukaan berengsel dengan baut pengunci untuk mencegah kebocoran material. Pengujian kinerja dilakukan menggunakan tiga rasio massa serbuk gergaji terhadap sekam padi: 5 kg:5 kg, 7,5 kg:7,5 kg, dan 10 kg:10 kg. Sampel sebanyak 100 g dikumpulkan dari tiga titik pengambilan sampel pada interval pencampuran 1 menit, 2 menit, dan 3 menit. Hasil penelitian menunjukkan rasio campuran rata-rata 60% serbuk gergaji dan 40% sekam padi per 100 g sampel, dengan kapasitas produksi 25 kg/detik menggunakan motor listrik 0,5 Hp pada 1430 rpm. Mesin yang dimodifikasi menunjukkan peningkatan kinerja penahanan dan homogenitas pencampuran yang konsisten di semua beban yang diuji. Temuan ini mendukung potensi otomatisasi lebih lanjut dari proses produksi baglog untuk memenuhi permintaan jamur tiram yang terus meningkat di Indonesia.

A Case Study Analysis on the Role of Value Management in the Construction Industry and the Philippines in Managing the Design

2025-12-26T07:22:34+00:00

Value management has not gained popularity among construction firms throughout the world. The study aims to evaluate the role of value management and the advantages that it gives in the construction industry, particularly the adaptation in the Philippines. A literature review was applied to the advantages and challenges of value management. Besides, a multiple case study analysis was conducted on how different countries have adapted value management. A questionnaire survey was used to, determine the challenges in the adaptation of value management, determine the measures to improve job performance obtained from applying value management and determine the benefits of value management in managing the design which was analyzed using Mean Item Score and Ranking. The results were used to compare the role of value management method practice in private company contractors and government contractors using Spearman’s Correlation Test and Hypothesis Testing. The involvement of the respondents in the use of VM was 46% and 70% of the respondents from the private and public contractors, respectively, showed that there is a healthy use of the method. Moreover, upon the utilization of Spearman’s correlation and hypothesis testing, it revealed that private and public contractors do not see these challenges in adapting value management, the measure to improve job performance in the adaptation of VM is seen effectively by both private and public contractor. The benefits of VM are significant to both of the private and public contractors.